it has become a lot easier for us when we found out that E was highly sensitive and had an way above average IQ - it makes us understand her a lot better and able to help her the right way.
It does seem like a lot of the listed fits the way you describe Rémy - one thing I have learn from E is that you also need to look at you child and say "this is X she/he is just the way she/he is" instead of trying to explain everything through a diagnoses
its nice as a help but easy to get caught up in the symptoms - this happend to us a bit and now we are instead looking at her as Emilie who is a carring, loving, highly empathic, smart young girl who also is highly sensitive, don't like big crowds and needs time alone and needs to know everything ahead